High-frequency waveguide structure

Abstract

For integration into a CMOS/BICMOS process, a high-frequency waveguide structure, a diode-bridge structure and an imaging/spectroscopy system and a method for manufacturing a high-frequency waveguide structure are provided, wherein a height of each of a first and a second conducting lines ( 11, 12 ) is higher than a width of each of the first and the second conducting lines ( 11, 12 ). The first and second conducting lines ( 11, 12 ) form a slotline waveguide, wherein the third conducting line ( 13 ) together with the first and the second conducting lines ( 11, 12 ) form a (co-)planar waveguide.

1 . A high-frequency waveguide structure, comprising:
 a substrate;   a first and a second conducting line located in a first layer (A) on the substrate; and   a third conducting line located in the symmetry plane (G) between the first and the second conducting lines wherein a height (h) of each of the first and the second conducting lines is higher than a width (w) of each of the first and second conducting lines.   
     
     
         2 . The high-frequency waveguide structure as claimed in any one of the preceding claims, wherein the third conducting line is located in a second layer (B, C) above or below the first layer (A). 
     
     
         3 . The high-frequency waveguide structure as claimed  claim 1 , wherein the first and the second conducting lines form a first waveguide for a slotline mode, and wherein the third conducting line together with the first and second conducting lines form a second waveguide for a planar waveguide-mode or a co-planar waveguide mode. 
     
     
         4 . The high-frequency waveguide structure as claimed in  claim 1 , wherein the coupling between the first and the second conducting line is higher than the coupling between the first or the second conducting line to the substrate. 
     
     
         5 . The high-frequency waveguide structure as claimed in  claim 1 , wherein the electric field of the slotline mode is mainly confined in-between the first and the second conducting lines. 
     
     
         6 . The high-frequency waveguide structure as claimed in  claim 1 , wherein the electric field of the slotline mode is substantially zero in the symmetry plane G of the first and the second conducting lines. 
     
     
         7 . The high-frequency waveguide structure as claimed in  claim 1 , wherein the high-frequency waveguide structure is integrated into a CMOS/BICMOS device. 
     
     
         8 . The high-frequency waveguide structure as claimed in  claim 1 , wherein the first and the second conducting lines are formed by a patterned thick metal layer. 
     
     
         9 . A diode-bridge structure being connected to a high-frequency waveguide structure according to  claim 1 , comprising:
 a first interconnecting structure between the first conducting line and the third conducting line comprising a first diode being connected with its cathode to the third conducting line and a first capacitor connected in series; and   a second interconnecting structure between the second conducting line and the third conducting line comprising a second diode being connected with its anode to the third conducting line and a second capacitor connected in series.   
     
     
         10 . The diode-bridge structure as claimed in  claim 9 , wherein the first and the second capacitors are located on two intermediate metal layers under the first and the second conducting lines, respectively. 
     
     
         11 . The diode-bridge structure as claimed in  claim 9 , wherein the first and the second diodes are located in the substrate under the first and the second conducting lines, respectively. 
     
     
         12 . An imaging/spectroscopy system for analyzing a sample using electromagnetic radiation in the sub-terahertz and/or terahertz region comprising:
 a transmitter for transmitting electromagnetic radiation in the sub-terahertz and/or terahertz region to the sample;   a receiver comprising high-frequency generator and a diode bridge structure according to  claim 9 , for receiving electromagnetic radiation in the sub-terahertz and/or terahertz region from the sample.   
     
     
         13 . The imaging/spectroscopy system as claimed in  claim 12 , wherein the high-frequency generator comprises a nonlinear transmission line for generating a signal with a very wide spectral content. 
     
     
         14 . The imaging/spectroscopy system as claimed in  claim 12 , wherein the high-frequency generator is connected to a high-frequency waveguide structure. 
     
     
         15 . Method for manufacturing a high-frequency waveguide structure comprising the steps of:
 providing a substrate;   providing a dielectric material on the substrate;   providing a thick metal layer in a first layer (A) on the dielectric material,   processing a first and a second conducting line by structuring the thick metal layer, wherein a height of each of the first and the second conducting lines is higher than a width of each of the first and a second conducting lines; and   processing a third conducting line located in the symmetry plane (G) between the first and the second conducting lines before or after processing the first and the second conducting line.